Potatoes were originally grown by native peoples of the Andes mountains in South America. Today, thousands of varieties are cultivated worldwide.
Though you may have noticed that potatoes tend to keep a long time, you may wonder precisely how long they last before spoiling.
This article tells you how long potatoes last — and how to tell whether they’re safe to eat.
Shelf life of potatoes
The length of time that potatoes stay fresh depends on several factors, including how they’re stored and whether they’ve been cooked.
In general, uncooked potatoes can last anywhere from 1 week to a few months. Cooler temperatures, such as those afforded by a pantry or root cellar, allow them to keep longer than at room temperature.
Once cooked, potatoes last up to 4 days in the refrigerator and 1 year in the freezer, though the quality of cooked mashed potatoes suffers with freezing.
The list below details shelf lives for various types of potatoes, including sweet, russet, Yukon Gold, red, and purple varieties.
- Fresh (cool temp near 50°F/10°C): 2–3 months
- Fresh (room temp): 1–2 weeks
- Raw (cut and stored in water): 24 hours
- Mashed (cooked & refrigerated): 3–4 days
- Baked (cooked & refrigerated): 3–4 days
- Boiled (cooked & refrigerated): 3–4 days
- Frozen (cooked): 10–12 months
- Instant (uncooked): Years
Summary: Uncooked potatoes stay fresh for a few weeks up to a few months. Once cooked, potatoes last for another 3–4 days when refrigerated or for up to 1 year when frozen.
Signs that potatoes have gone bad
Even if you keep shelf life in mind, you should still check potatoes for telltale signs of spoilage.
Whole fresh potatoes
Raw potatoes should be firm to the touch with tight skin that’s free of large bruises, black spots, or other blemishes.
If a potato has become soft or mushy, you should throw it out.
Though it’s normal for potatoes to smell earthy or nutty, a musty or moldy odor is a hallmark of spoilage.
Sometimes, a potato might have a blemish or bad spot on the inside that you can’t see from the outside. A strong smell coming from an otherwise fresh-looking potato is a warning that the inside may have rotted or started to mold.
You should always dispose of foul-smelling potatoes.
What about sprouted potatoes?
Sprouts are a sign of imminent spoilage in potatoes.
Sprouts form from potatoes’ “eyes,” which are merely small bumps or indentions where the tubers stem and sprout new plants.
Although sprouts may look unappealing, recently sprouted potatoes are still safe to eat as long as you remove the sprouts. You can do so by simply snapping them off with your fingers.
You shouldn’t eat the sprouts because they contain solanine, chaconine, and other toxic glycoalkaloids. These compounds can have serious side effects, including neurological and digestive symptoms like headaches, vomiting, and diarrhea.
These toxins may also exist in any part of the potato that has a greenish tint. Therefore, it’s best to cut away any green parts on the skin or flesh to avoid getting sick.
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If your potatoes have sprouted, it’s best to eat them soon. As sprouts grow, they suck sugars and nutrients from the plant, causing it to shrivel, shrink, and lose its crunch.
It’s not always as easy to tell when cooked potatoes have gone bad.
In some cases, cooked potatoes have a strong odor or visible mold that indicates spoilage. Yet, in other cases, this food may harbor harmful bacteria without any noticeable signs.
Especially once cooked, potatoes are a high-risk food for bacteria that can cause food poisoning. That’s because they hold a lot of moisture, are slightly acidic, and contain some protein.
Therefore, it’s best to eat them within 4 days of cooking and always reheat them to 165°F (74°C) to kill any bacteria that may have formed.
Summary: Some signs that uncooked potatoes have spoiled include dark spots on the skin, a soft or mushy texture, and a foul odor. Cooked potatoes may have mold but can also spoil without any noticeable signs.
The health risks of eating spoiled potatoes
Cooked potatoes carry a high risk of food poisoning.
After a few days, they may begin to harbor pathogens and bacteria that could result in illnesses, such as salmonella, listeria, botulism, and staphylococcal food poisoning.
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If you have a foodborne illness, you might experience some of the following symptoms:
- stomach cramps
- muscle aches
In severe cases, these symptoms could result in dehydration, hospitalization, and even death.
Thus, you should throw out any cooked potatoes that are older than 4 days.
Additionally, if you ever spot mold on cooked potatoes, you should dispose of them immediately. Mold may appear as fuzz or a few dark spots that are brown, black, red, white, or bluish gray.
Summary: Potatoes sometimes cause food poisoning. To avoid getting sick, be sure to eat cooked potatoes within 4 days and immediately throw away any potatoes that show signs of mold.
The best way to store potatoes
Paying close attention to storage conditions can help potatoes last longer.
Given that warm temperature and moisture encourage sprouting, and exposure to light increases the rate at which glycoalkaloid toxins form, you shouldn’t store raw potatoes on the counter or in the open.
Rather, keep them in a cool, dark, dry place, such as a pantry, cellar, cupboard, or cabinet that keeps out sunlight.
In addition, uncooked potatoes are best left in a container — such as a box, open bowl, or perforated bag — that allows air to circulate around the tubers. They should never be sealed in airtight bags or containers.
Although cool temperatures are ideal for potato storage, fresh potatoes should never be kept in the refrigerator or freezer. Doing so could result in browning and softening, a higher sugar content, and even an increase in acrylamides.
Acrylamides are compounds sometimes formed in starchy foods after they’ve been cooked at high temperatures — think french fries or potato chips — and are classified as probable or likely carcinogens by some organizations.
When possible, keep your potatoes separate from other types of produce. This will minimize their exposure to ethylene gases that might accelerate sprouting or spoilage.
As a rule of thumb, cooked potatoes should be refrigerated at 40°F (4°C) or below, while frozen potatoes should be kept at 0°F (-18°C).
Summary: It’s best to store raw potatoes in a cool, dark place that allows air circulation. Cooked potatoes should be kept at 40°F (4°C) or below when refrigerated and 0°F (-18°C) or below when frozen.
Potatoes are a starchy root vegetable known partly for their long shelf life.
Yet, how long they last depend on how they’re stored and cooked.
If stored in a cool, dark, dry place, raw potatoes can last for several months. But once cooked, they should be eaten or frozen within a few days to prevent foodborne illness.
Be sure to throw away potatoes that have a strong odor or mold growth.